Sorry for the trouble! The app isn't actually damaged — macOS shows this message because the app isn't registered (signed) with Apple yet, so it gets blocked the first time you open it.
Here's how to open it:
Move the app into your Applications folder.
Open Terminal (Applications → Utilities → Terminal) and paste this, then press Enter:
xattr -dr com.apple.quarantine "/Applications/hun0fx Pixel Studio.app"
Open the app again — it should start normally from now on.
Please also check that you downloaded the right zip: arm64 for Apple Silicon Macs (M1–M4), x64 for Intel Macs. (Apple menu → About This Mac shows which one you have.)
If it still doesn't work, or you'd rather not use it, I'm happy to refund you at any time — just reply here or send me a message and I'll take care of it right away.